Please contact us.
It is not available with JIS approval.
Please do not fix the lever. We recommend operating the lever (draining water) 1 or 2 times per month, but this is not possible if the lever is fixed. Besides, it will be very dangerous as it will prevent the relief valve from operating properly to protect the system.
Please use metal pipes.
We recommend AL-150T and AL-140T with excellent tightness.
We recommend the AL-150 Series safety relief valve, in which SCS14A is used for the valve and valve seat.
For the AL-150 Series safety relief valve standard product, SCS14A (equivalent to SUS316) with superior corrosion resistance is used for the valve and valve seat.
The safety relief valve equipped with an O-ring is available, using a soft seat for the trim parts to provide the valve seat with excellent tightness. (Model: AL-150T/-150TR/-150TML/-140T)
For oil use, please contact us for further information.
Regarding discharge capacity, selection practice differs among regions, industries and applications etc. The safest way is to select a safety valve covering the maximum flow rate of the pressure reducing valve.
As for the set pressure, please refer to the following table.
For the lift type safety valve, a lift of valve seat is more than 1/40 or under 1/4 of an inside diameter of a valve seat opening, and a flow passage area (a curtain area) of valve port becomes the smallest in flow passage area when a valve disc opens.
For the full bore type safety valve, the flow passage area at valve seat is bigger enough than the nozzle throat area at the inlet side.
In Yoshitake's lineup, lift type models are named AL-XX series and full bore type models are named AF-XX series.
There are two kinds of "back pressure" of a safety valve.
1. Accumulated back pressure (Pressure at the outlet side of the valve, which is generated by the flow at the outlet side when the valve starts to blow.)
2. Existing back pressure (Pressure which already exists before the valve starts to flow. The pressure is generated by the other sources of supply).
When the back pressure generated as the valve starts to blow exceeds the permissible value (approximately 10% of the blow out pressure), the activation in closing is badly influenced. JIS B 8210 requires deciding the back pressure of blowing pipe according to a safety valve subject to a limit of the lowest back pressure.
A safety valve is mainly used to ensure safety of a vapor (steam or gas) generator, which operates instantly and automatically when the vapor pressure exceeds the specified value (Referring to JIS B 8210). A relief valve is mainly used to relieve excess liquid (water / oil) pressure. It is automatically opens depending on the pressure increase, in case the liquid pressure reaches the set pressure.
A safety relief valve is mainly installed on pipings, and it can be used for both gas and liquid.
No, because adhering material or stuck deposit can cause malfuction.
It depends on model.
Please specify the set pressure at the time of order, or re-adjustment at factory is required. Please contact us or our local distributor in your country/area.
Do not install a strainer on the inlet side.
No, they have to be serviced at factory.
It depends on the valve's structure.
1) Closed type: only from the outlet
2) Open type: the fluid can come out from open part of the spring case, cap and lever part (sliding part of the spindle) and back pressure pipe.
The part cannot be plugged because it adjusts the blowdown by adjusting back pressure above the valve disc.
No, they cannot.
Safety valves stop blowing only if the inlet pressure drops to the re-seating pressure.
Set pressure up to 0.129MPa: by every 0.002MPa
Set pressure 0.13-0.26MPa: by every 0.005MPa
Set pressure higher than 0.26MPa: up to the second after decimal point (in MPa)
To drain condensate (water) inside the safety valve body.
Both types can be selected as long as the valve satisfies the required discharge capacity.
Please use it within its working pressure.
Please refer to "Guidelines for Installing Safety Valve."
Rate of allowable overpressure is called accumulation.
Yes, please contact us.